Zero-overhead profiling via em emanations

Abstract

This paper presents an approach for zero-overhead profiling (ZOP). ZOP accomplishes accurate program profiling with no modification to the program or system during profiling and no dedicated hardware features. To do so, ZOP records the electromagnetic (EM) emanations generated by computing systems during program execution and analyzes the recorded emanations to track a program's execution path and generate profiling information. Our approach consists of two main phases. In the training phase, ZOP instruments the program and runs it against a set of inputs to collect path timing information while simultaneously collecting waveforms for the EM emanations generated by the program. In the profiling phase, ZOP runs the original (i.e., uninstrumented and unmodified) program against inputs whose executions need to be profiled, records the waveforms produced by the program, and matches these waveforms with those collected during training to predict which parts of the code were exercised by the inputs and how often. We evaluated an implementation of ZOP on several benchmarks and our results show that ZOP can predict path profiling information for these benchmarks with greater than 94% accuracy on average.